Methods for forming surface features using self-assembling masks

ABSTRACT

A method for producing surface features and an etch masking method. A combination is provided of a block copolymer and additional material. The block copolymer includes a first block of a first polymer covalently bonded to a second block of a second polymer. The additional material is miscible with the first polymer. A film is formed of the combination directly onto a surface of a first layer. Nanostructures of the additional material self-assemble within the first polymer block. The film of the combination and the first layer are etched. The nanostructures have an etch rate lower than an etch rate of the block copolymer and lower than an etch rate of the first layer. The film is removed and features remain on the surface of the first layer. Also included is an etch masking method where the nanostructures mask portions of the first layer from said etchant.

This application is a continuation application claiming priority fromSer. No. 11/926,722 filed Oct. 29, 2007, now U.S. Pat. No. 7,828,986,issued Nov. 9, 2010.

FIELD OF THE INVENTION

The invention generally relates to methods of masking and formation ofsurface structures in semiconductor materials.

BACKGROUND OF THE INVENTION

As integrated circuit dimensions continue to decrease, resistivecapacitive (RC) delay, crosstalk noise, and power dissipation of theinterconnect structure may become limiting factors for ultra-large-scaleintegration of integrated circuits. Materials with low dielectricconstants may be used to replace silicon dioxide as inter-metaldielectrics. Alternatively, air bridge (gap) structures may replace thedielectrics surrounding the metal wire, where air, in principle, mayprovide an even lower dielectric constant. Current integration schemesemploying air gaps may utilize methods employing removal of asacrificial organic polymer, high pressure chemical vapor deposition(CVD) to pinch off formed air gaps at the entrance providing a cappedstructure, or multi-layered structures combined with multi-steplithographic exposure, developing, and etching. There exists a need fora method having reduced complexity for producing nanoscale air gapstructures.

SUMMARY OF THE INVENTION

The present invention relates to a method for producing surfacefeatures, comprising:

providing a combination of a block copolymer with additional material,said block copolymer comprising a first block of a first polymer, saidfirst block being covalently bonded to a second block of a secondpolymer to form a repeating unit of the block copolymer, said first andsecond polymers being different, said additional material being misciblewith said first polymer;

adhering a first layer onto a surface of a substrate, wherein said firstlayer comprises an organic compound;

forming a film of said combination directly onto a surface of said firstlayer, wherein in response to said forming, nanostructures of saidadditional material self-assemble within said first polymer block, saidnanostructures self-aligning perpendicular to said surface of said firstlayer; and

etching said film of said combination and said first layer, saidnanostructures having an etch rate lower than an etch rate of said blockcopolymer, said nanostructures having an etch rate lower than an etchrate of said first layer, wherein said film is removed and featuresremain on said surface of said first layer after said etching.

The present invention relates to an etch masking method, comprising:

forming a first film on a surface of a substrate, wherein said firstfilm comprises an organic compound;

forming a second film over said first film, said second film comprisinga combination of a block copolymer and an inorganic material, said blockcopolymer comprising a first block of a first polymer and a second blockof a second polymer, said inorganic material selectively miscible insaid first block of said first polymer, wherein nanostructures of saidinorganic material self-assemble in said first block of said blockcopolymer after said forming said second film; and

etching by an etchant simultaneously said block copolymer and said firstfilm, wherein said nanostructures mask portions of said first film fromsaid etchant, said nanostructures having an etch rate lower than saidfirst film and said nanostructures having an etch rate lower than saidblock copolymer.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention are set forth in the appended claims. Theinvention itself, however, will be best understood by reference to thefollowing detailed description of illustrative embodiments when read inconjunction with the accompanying drawings.

FIG. 1 is an illustration of a flow chart representing a method forproducing surface features, in accordance with embodiments of thepresent invention.

FIG. 2 is an illustration of an embodiment of the present inventioncomprising a substrate having a first layer adhered onto a surface ofthe substrate, in accordance with embodiments of the present invention.

FIG. 3 is an illustration of the embodiment of FIG. 2 after the blockcopolymer of the film of the combination in FIG. 2 has beensubstantially removed, in accordance with embodiments of the presentinvention.

FIG. 4 is an illustration of the embodiment of FIG. 2 after the film ofthe combination has been removed by the etching step of FIG. 1, inaccordance with embodiments of the present invention.

FIG. 5 is a tilted SEM image of a cross-section of a sample showing thetransfer layer after etching, in accordance with embodiments of thepresent invention.

FIG. 6 is a table illustrating a range of molecular weights for PS andPEO in the PS-b-PEO block copolymer used to form nanopores in a transferlayer, in accordance with embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Although certain embodiments of the present invention will be shown anddescribed in detail, it should be understood that various changes andmodifications may be made without departing from the scope of theappended claims. The scope of the present invention will in no way belimited to the number of constituting components, the materials thereof,the shapes thereof, the relative arrangement thereof, etc., and aredisclosed simply as examples of embodiments. The features and advantagesof the present invention are illustrated in detail in the accompanyingdrawings, wherein like reference numerals refer to like elementsthroughout the drawings. Although the drawings are intended toillustrate the present invention, the drawings are not necessarily drawnto scale.

A monomer as used herein is a molecule that can undergo polymerizationthereby contributing constitutional units to the essential structure ofa macromolecule, an oligomer, a block, a polymer, a chain, and the like.

A polymer as used herein is a macromolecule comprising multiplerepeating smaller units or molecules (monomers) derived, actually orconceptually, from smaller units or molecules, bonded togethercovalently or otherwise. The polymer may be natural or synthetic.

A copolymer as used herein is a polymer derived from more than onespecies of monomer.

A block copolymer as used herein is a copolymer that comprises more thanone species of monomer, wherein the monomers are present in blocks. Eachblock of the monomer comprises repeating sequences of the monomer. Aformula (1) representative of a block copolymer is shown below:(A)_(a)-(B)_(b)-(C)_(c)-(D)_(d)  (1)

wherein A, B, C, and D represent monomer units and the subscripts “a”,“b”, “c”, and “d”, represent the number of repeating units of A, B, C,and D respectively. The above referenced representative formula is notmeant to limit the structure of the block copolymer used in anembodiment of the present invention. The aforementioned monomers of thecopolymer may be used individually and in combinations thereof inaccordance with the method of the present invention.

In one example, a block copolymer may have blocks of two differentpolymers. A formula (2) representative of such a block copolymer isshown below:(A)_(m)-(B)_(n)  (2)

where subscripts “m” and “n” represent the number of repeating units ofA and B, respectively. The notation for such a block copolymer may beabbreviated as A-b-B, where A represents the polymer of the first block,B represents the polymer of the second block, and -b-denotes that it isa block copolymer of blocks of A and B. For example, PS-b-PEO mayrepresent a block copolymer of polystyrene (PS) and poly(ethylene oxide)(PEO).

A crosslinkable polymer as used herein is a polymer having a region inthe polymer from which at least one polymer chain may emanate, and maybe formed by reactions involving sites or groups on existing polymers ormay be formed by interactions between existing polymers. The region maybe an atom, a group of atoms, or a number of branch points connected bybonds, groups of atoms, or polymer chains. Typically, a crosslink is acovalent structure but the term is also used to describe sites of weakerchemical interactions, portions of crystallites, and even physicalinteractions such as phase separation and entanglements.

A nanostructure as used herein is a structure on the order of 1nanometer (nm) to 500 nm in dimension. Examples of the structure mayinclude but are not limited to nanorods, nanosheets, nanospheres,nanocylinders, nanocubes, nanoparticles, nanograins, nanofilaments,nanolamellae, and the like having solid composition and a minimalstructural diameter in a range from about 1 nm to about 500 nm. Furtherexamples of the structure may include but are not limited to sphericalnanopores, cylindrical nanopores, nanotrenches, nanotunnels, nanovoids,and the like having their void or shape defined by the material ormatrix that surrounds them and having a diameter in a range from about 1nm to about 500 nm.

A substrate, as used herein, is a physical body (e.g., a layer or alaminate, a material, and the like) onto which a polymer or polymericmaterial may be deposited or adhered. A substrate may include materialsof the IUPAC Group 11, 12, 13, and 14 elements; plastic material;silicon dioxide, glass, fused silica, mica, ceramic, metals deposited onthe aforementioned substrates, combinations thereof, and the like. Forexample, a substrate may include a dielectric coated silicon wafer suchas those used in semiconductor manufacturing.

FIG. 1 is an illustration of a flow chart representing a method forproducing surface features. Step 105 provides a block copolymer, wherethe block copolymer may comprise a first block of a first polymercovalently bonded to a second block of a second polymer, where the firstblock and second block may be different. For example, the blockcopolymer may be a block copolymer of polystyrene and poly(ethyleneoxide), PS-b-PEO.

The use of PS-b-PEO as the block copolymer is not meant to limit thetype of the block copolymer that may be used in an embodiment of thepresent invention. The block copolymer may be an organic blockcopolymer. Specific examples of a first polymer may include but are notlimited to poly(ethylene oxide) (or poly(ethylene glycol)),poly(propylene glycol), poly(alkylene oxides), poly(acrylic acids),poly(methacrylic acids), poly(dimethylamino ethylmethacrylates),poly(hydroxyalkyl methacrylates), poly(alkyleneoxide acrylates),poly(alkyleneoxide methacrylates), poly(hydroxystyrenes),polycarbohydrates, poly(vinyl alcohols), poly(ethylene imines),polyoxazolines, polypeptides, poly(vinyl pyridines), polyacrylamides,poly(methyl vinyl ethers), poly(vinyl carboxylic acid amides),poly(N,N-dimethylacrylamides), and the like. Specific examples of asecond polymer may include but are not limited to polystyrene,poly(α-methylstyrene), polynorbornene, polylactones, polylactides,polybutadiene, polyisoprene, polyolefins, polymethacrylates,polysiloxanes, poly(alkyl acrylates), poly(alkyl methacrylates),polyacrylonitriles, polycarbonates, poly(vinyl acetates), poly(vinylcarbonates), polyisobutylenes, and the like. The block copolymer may beconfigured such that the first polymer and second polymer are notdienes. Block copolymers formed from the aforementioned first and secondpolymers may be used individually and in combinations thereof inaccordance with the method of the present invention. The molecularweight of each block of the block copolymer may be in a range from about1,500 g/mol to about 50,000 g/mol. For example, for a PS-b-PEO blockcopolymer, the PS may have a molecular weight in a range from about 3.0kilograms/mole (kg/mol) to about 19.0 kg/mol, and the poly(ethyleneoxide) may have a molecular weight in a range from about 4.0 kg/mol toabout 12.0 kg/mol.

Step 110 provides additional material which may be selectively misciblewith the first polymer of the block copolymer. For example, theadditional material may be an organosilicate precursor, such as acopolymer of methyltrimethoxysilane and tetraethylorthosilicate, wherethe organosilicates may have a higher miscibility in the first polymerof the block copolymer. In the block copolymer example above, theorganosilicate may be selectively miscible in the PEO block of thePS-b-PEO block copolymer. The block copolymer may be configured suchthat the block in which the additional material is selectively miscible,is not a diene.

The use of the copolymer of methyltrimethoxysilane andtetraethylorthosilicate as the additional material in this example isnot meant to limit the type of additional material that may be used inembodiments of the present invention. The additional material may be aninorganic material. Other materials that may be used include, but arenot limited to an inorganic homopolymer, a crosslinkable homopolymer, acombination thereof, and the like. The crosslinkable homopolymer may bea silsesquioxane having the general formula (RSiO_(1.5))_(n), wherein Rmay be a hydrido group or an alkyl group having 1 to 3 carbon atoms,wherein n may be in a range from about 10 to about 500, and wherein thecrosslinkable homopolymer may have a molecular weight in a range fromabout 600 g/mol to about 30,000 g/mol. Other crosslinkable homopolymersmay include inorganic crosslinkable polymers; polysilanes; polygermanes;polysirazanes; carbosilanes; borazoles; carboranes; amorphous siliconcarbides; and the like. The aforementioned crosslinkable polymers may beused individually or in combinations thereof in accordance with themethod of the present invention.

In step 115, the block copolymer and the additional material may becombined to form a combination of block copolymer and the additionalmaterial. The additional material may selectively migrate to blockcopolymer domains in which the additional material is selectivelymiscible, such as the first polymer block for example. In the case of asilicon-containing additional material, the combination may havesilicon-rich block copolymer domains (those domains where the additionalmaterial is selectively miscible) and silicon poor block copolymerdomains (those domains wherein the additional material is notselectively miscible). For example, in one embodiment blocks of thefirst polymer may have at least 7 weight percent silicon while blocks ofthe second polymer may have less than 4 weight percent silicon.

In step 120, a first layer may be adhered to the surface of a substrate,where the first layer may comprise an organic compound. The first layermay comprise a pattern transfer layer comprising a hydroxystyrene-basedcrosslinkable polymer, polydimethylglutarimide, poly(vinylbenzoic acid),polyhydroxystyrenes, polyimides, or a combination thereof. In oneembodiment, the first layer may be an organic interlayer planarizationlayer.

In step 125, a film of the combination formed in step 115 is formeddirectly onto a surface of the first layer. In response to forming thefilm, nanostructures of the additional material may self-assemble withinthe first polymer block and self-align perpendicular to the surface ofthe first layer, since the block copolymer may form aligned segregatedstructures of the first polymer block (containing the additionalmaterial) and the second polymer block. The resulting morphology of theadditional material nanostructures may be controlled by varying factorswhich may change the morphology of the block copolymer segregatedstructures, such as the molecular weights and compositions of the firstand second blocks of the block copolymer

The combination of the block copolymer and the additional material maybe formed in a solvent solution and cast as a solution, which mayrequire solvent removal for complete film formation. A thin film of thecombination may be spin coated onto a substrate, where a spin speed maybe in a range from about 50 rpm to about 5,000 rpm. The combination maybe spin coated at room temperature without a post-drying process.Alternatively, a film sample on a substrate may be thermally annealed,after forming the film, at a temperature of about 100° C. for about 10hours, for example. Also, a film sample on a substrate may be vaporannealed, after forming the film on the substrate, by annealing theadhering film under organic solvent vapor at room temperature (about 25°C.) from about 10 hours to about 15 hours, for example. Nanostructurescomprising the additional material may self-assemble during or afterfilm formation on a substrate or layers deposited thereon.

The spin coating process used is not meant to limit the type ofprocesses that may be used in an embodiment of the present invention.Other processes such as chemical vapor deposition (CVD), photochemicalirradiation, thermolysis, spray coating, dip coating, doctor blading,and the like may be used individually and in combinations thereof inaccordance with the method of the present invention.

The formation of the self-assembled nanostructures may be accomplishedby forming the film on the substrate, thermal annealing after formingthe film on the substrate, vapor annealing after forming said film onthe substrate, a combination thereof, or any other process whichprovides a means for forming the structures.

FIG. 2 is an illustration of an embodiment of the present inventioncomprising a substrate 200 having a first layer 210 adhered onto asurface of the substrate 200, where a film 215 comprising a combinationof a block copolymer and additional material has been formed over asurface of the first layer 210. The substrate 200 may comprise a singlelayer. The substrate 200 may comprise a plurality of layers, such assubstrate layers 200A and 200B in the embodiment illustrated in FIG. 2.Nanostructures 220 of the additional material may self-assemble withinthe film 215 of the combination upon formation of the film 215 on thesurface of the first layer 210. The film 215 comprises a nanostructure220 and a nanostructural element 230 alternating with respect to eachother in a direction parallel to the top surface of the substrate 200 toform a repeating pattern of the nanostructure and the nanostructuralelement. The nanostructures 220 may comprise the additional material inthe first polymer block of the block copolymer. The nanostructuralelements 230 may comprise the additional material in the second polymerblock of the block copolymer.

Referring to FIG. 1, in step 130 the film of the combination and thefirst layer may be etched simultaneously. For example, the film of thecombination and the first layer may be etched in a single etching step.The etching may utilize an etchant such as a gas plasma of oxygen,argon, helium, the like, or a combination thereof. The nanostructuresmay have an etch rate (e.g. rate at which an amount or thickness ofmaterial is removed per unit of time) which is lower than that of thefirst layer and which is lower than the etch rate of the blockcopolymer. The rate of the etch rate of the block copolymer to the etchrate of the nanostructures may be greater than 5:1, such as greater than100:1. For example, the etch rate of polystyrene in an oxygen plasma maybe about 2.7 nm/second whereas the etch rate of the organosilicate underthe same conditions may be less than about 0.03 nm/second. In such acase, as the block copolymer is etched away more rapidly that thenanostructures, the nanostructures will act as an in-situ mask to blockthe etching of areas of the first layer directly beneath thenanostructures. Simultaneously etching the first layer and the film ofthe combination may thus result in removal of the film (or portionsthereof) and leaving features on the surface of the first layer.

FIG. 3 is an illustration of the embodiment of FIG. 2 after the blockcopolymer of the film 215 of the combination in FIG. 2 has been removed,where the nanostructures 220 remain and mask the portions 305 of thefirst layer 210 directly beneath the nanostructures 220. After theetching process etches away (removes) the block copolymer and while theetchant continues to more slowly etch the nanostructures 220, theetchant may continue to etch the areas 300 of the first layer which arenot masked by the nanostructures 220. As the process completes, thenanostructures 220 may be etched away to leave intact portions 305 ofthe first layer 210 which were masked by the nanostructures 220 and toleave features on the surface of the first layer 210, where the etchantremoved unmasked areas 300 of the first layer 210.

FIG. 4 is an illustration of the embodiment of FIG. 2 after the film 215of the combination (or portions thereof) has been removed by the etchingstep 130 of FIG. 1. Features 400 remain on a surface of the first layer210 as holes (i.e. hole regions) 405 and within in the first layer 210as nanopores 410. Each hole region 405 is disposed between successivenanoshapes 435. Each hole region 405 includes therein a portion of asurrounding ambient atmosphere 430. The top surface 425 of eachnanoshape 435 is directly exposed to the surrounding ambient atmosphere430.

EXAMPLE 1

Propylene glycol mono methyl ether acetate (PGMEA) was used to make 1%by weight (wt %) solutions of each of PS-b-PEO and an organosilicate.The organosilicate precursor (PMS) was a copolymer ofmethyltrimethoxysilane and tetraethylorthosilicate with an approximatemolecular weight of 2000 grams/mole (g/mol). The two solutions werecombined with the block copolymer PS-b-PEO in a PS-b-PEO/PMS ratio ofabout 30/70 weight/weight (wt/wt). The PS-b-PEO (obtained from PolymerSource, Inc.) comprised a first block of a first polymer, PEO, and asecond block of a second polymer, PS, where the molecular weight of thePS block was about 19.0 kg/mol, and the molecular weight of the PEOblock was about 12.3 kg/mol. A hydroxystyrene-based crosslinkablepolymer (NFC1400, JSR Micro) or polydimethylglutarimide (PMGI,MicroChem) was used to spin-cast a 180 nm thick transfer layer onto aclean Si (100) wafer substrate. The substrate with transfer layer wasbaked for 1 minute at 190° C. The combination solution was spun-cast atabout 1000 rpm onto a surface of the transfer layer on the substrateunder chloroform vapor.

The layered samples were etched using an anisotropic oxygen plasma forabout 60 seconds in a Surface Technology Systems Multiplex tool, whichutilizes an inductively coupled plasma configuration. The oxygenpressure was about 6 milliTorr (mTorr), the oxygen flow rate was about30 standard cubic centimeters/minute (sccm), the coil power was about300 watts (W), the platen power was about 20 W, and the sampletemperature was held at approximately 20° C.

FIG. 5 is a tilted SEM image of a cross-section of the sample preparedabove showing the transfer layer 500, where features 505 (shown as anarray of holes 510 and cylindrical nanopores 515 oriented perpendicularto the surface of the thick organic transfer layer 500) remain on thesurface of the transfer layer 500 and within the transfer layer 500after removal of the block copolymer layer by etching.

EXAMPLE 2

The size of the resulting nanopores may be controlled by changing themolecular weights of the first and second blocks of the block copolymer.FIG. 6 is a table illustrating a range of molecular weights for PS andPEO in the PS-b-PEO block copolymer used to form nanopores in a transferlayer as described in Example 1. The molecular weights of PS-b-PEO rangefrom PS19k-b-PEO12.3 k (19 kg/mol for PS and 12.3 kg/mol for PEO) toPS9.5 k-b-PEO9.5 k (9.5 kg/mol for PS and 9.5 kg/mol for PEO) to PS3.8k-b-PEO4.8 k (3.8 kg/mol for PS and 4.8 kg/mol for PEO), and resulted innanopore diameters of 25 nm, 15 nm, and 8 nm respectively.

The foregoing description of the embodiments of this invention has beenpresented for purposes of illustration and description. It is notintended to be exhaustive or to limit the invention to the precise formdisclosed, and obviously, many modifications and variations arepossible. Such modifications and variations that may be apparent to aperson skilled in the art are intended to be included within the scopeof this invention as defined by the accompanying claims.

What is claimed:
 1. A method for producing surface features, comprising:providing a combination of a block copolymer with additional material,said block copolymer comprising a first block of a first polymer, saidfirst block being covalently bonded to a second block of a secondpolymer to form a repeating unit of the block copolymer, said first andsecond polymers being different, said additional material beingselectively miscible with said first polymer; adhering a first layeronto a surface of a substrate, wherein said first layer comprises anorganic compound; forming a film of said combination directly onto asurface of said first layer, wherein in response to said forming,nanostructures of said additional material self-assemble within saidfirst polymer block, said nanostructures self-aligning perpendicular tosaid surface of said first layer; and etching said film of saidcombination and said first layer, said nanostructures having an etchrate lower than an etch rate of said block copolymer with respect tosaid etching, said nanostructures having an etch rate lower than an etchrate of said first layer with respect to said etching, whereincompletion of said etching results in: (i) removal of all of said filmand a first portion of said first layer, (ii) leaving a remainingportion of said first layer comprising a plurality of nanoshapes on saidsurface of said substrate such that said nanoshapes are distributed in afirst direction that is parallel to the surface of the substrate, (iii)leaving a plurality of hole regions distributed in the first directionsuch that each hole region is disposed between successive nanoshapes ofsaid plurality of nanoshapes, and (iv) leaving said substrate unetchedby said etching, wherein said nanoshapes are encompassed in theirentirety by the remaining portion of said first layer, wherein each holeregion includes therein a portion of a surrounding ambient atmosphere,and wherein said removal of all of said film results in a top surface ofeach nanoshape being directly exposed to said surrounding ambientatmosphere.
 2. The method of claim 1, wherein said first layer comprisesa hydroxy styrene-based cross linkable polymers.
 3. The method of claim1, wherein said first layer comprises a polyhydroxystyrenes.
 4. Themethod of claim 1, wherein said block copolymer is an organic blockcopolymer of polystyrene and poly(ethylene oxide).
 5. The method ofclaim 1, wherein said additional material is an organosilicateprecursor.
 6. The method of claim 5, wherein said additional material isa copolymer of methylmethoxysilane and tetraethylorthosilicate.
 7. Themethod of claim 1, wherein said first layer comprisespolydimethylglutarimide.
 8. The method of claim 1, wherein said firstlayer comprises a polyimide.
 9. The method of claim 1, wherein saidfirst layer comprises poly(vinylbenzoic acid).
 10. The method of claim1, wherein the nanostructures of said additional material have amorphology, and wherein the method further comprises: controlling themorphology of the nanostructures of said additional material byselecting the first block of the first polymer and the second block ofthe second polymer based on the molecular weight and composition of thefirst block of the first polymer and the molecular weight andcomposition of the second block of the second polymer.
 11. The method ofclaim 1, said formed film comprising nanostructural elements and saidnanostructures alternating with respect to each other in the firstdirection to form a repeating pattern of the nanostructures and thenanostructural elements, said formed film comprising the additionalmaterial in the first block of the first polymer and in the second blockof the second polymer.
 12. An etch masking method, comprising: forming afirst film on a surface of a substrate, wherein said first filmcomprises an organic compound; forming a second film over said firstfilm, said second film comprising a combination of a block copolymer andan inorganic material, said block copolymer comprising a first block ofa first polymer and a second block of a second polymer, said inorganicmaterial selectively miscible in said first block of said first polymer,wherein nanostructures of said inorganic material self-assemble in saidfirst block of said block copolymer after said forming said second film;and etching by an etchant simultaneously said combination and said firstfilm, said nanostructures having an etch rate lower than said first filmwith respect to said etching, said nanostructures having an etch ratelower than said block copolymer with respect to said etching, whereincompletion of said etching results in: (i) removal of all of said secondfilm and a first portion of said first film, (ii) leaving a remainingportion of said first film comprising a plurality of nanoshapes on saidsurface of said substrate such that said nanoshapes are distributed in afirst direction that is parallel to the surface of the substrate, (iii)leaving a plurality of hole regions distributed in the first directionsuch that each hole region is disposed between successive nanoshapes ofsaid plurality of nanoshapes, and (iv) leaving said substrate unetchedby said etching, wherein said nanoshapes are encompassed in theirentirety by the remaining portion of said first film, wherein each holeregion includes therein a portion of a surrounding ambient atmosphere,and wherein said removal of all of said film results in a top surface ofeach nanoshape being directly exposed to said surrounding ambientatmosphere.
 13. The method of claim 12, wherein said first filmcomprises poly(vinylbenzoic acid).
 14. The method of claim 12, whereinsaid first film comprises a polyhydroxystyrene.
 15. The method of claim12, wherein said inorganic material comprises a copolymer ofmethylmethoxysilane and tetraethylorthosilicate.
 16. The method of claim12, wherein said first film comprises a hydroxy styrene-based crosslinkable polymer.
 17. The method of claim 12, wherein said first filmcomprises a polyimide.
 18. The method of claim 12, wherein said firstfilm comprises polydimethylglutarimide.
 19. The method of claim 12,wherein the nanostructures of said inorganic material have a morphology,and wherein the method further comprises: controlling the morphology ofthe nanostructures of said inorganic material by selecting the firstblock of the first polymer and the second block of the second polymerbased on the molecular weight and composition of the first block of thefirst polymer and the molecular weight and composition of the secondblock of the second polymer.
 20. The method of claim 12, said secondformed film comprising nanostructural elements and said nanostructuresalternating with respect to each other in the first direction to form arepeating pattern of the nanostructures and the nanostructural elements,said second formed film comprising the inorganic material in the firstblock of the first polymer and in the second block of the secondpolymer.